Learning & memory

Question 1

key features of life-long learning

Answer 1

1. transfer & adaptation
2. overcoming catastrophic forgetting (not forgetting previous training when learning new tasks)
3. flexibility (exploiting task similarity & task-agnostic learning)
4. Noise tolerance
5. Resource efficiency & sustainability

Question 2

HM

Answer 2

lost part of the medial temporal lob incl. hippocampus. HM had anterograde amnesia which provided the first evidence for localisation of memory (medial temporal lobe being responsible for transition from STM to LTM as HM had LTM and working memory but couldnt form new explicit LTM)

Question 3

classification of long term memory

Answer 3

Explicit (declarative) -> semantic (facts) & episodic (events)

Implicit (non-declarative) -> unconscious and measured by actions (four types)

Question 4

Types of implicit memory & their locations

Answer 4

Priming (neocortex)
Procedural (striatum of basal ganglia)
Associative (classical conditioning) -> emotional responses (amygdala), skeletal musculature (cerebellum)
Nonassociative: habituation & sensitisation (reflex pathways)

Question 5

Monkey experiment on working memory

Answer 5

Using treat found under certain object -> examine working memory of which object hides reward after a variable delay.

Lesions of the medial temporal lobe showed more removed correlated to lower memory score.

With the lesions, percentage correct was same as normal with a minimal delay (8-10 secs) however rapidly dropped off from 15-30seconds therefore: medial temporal lobe is involved in the transition from short term to long term memory

Question 6

types of working memory

Answer 6

Two subsystems:
Verbal information
Visuospatial information

Functioning of these subsystems is coordinated by the executive control processes

Question 7

Areas involved in verbal working memory

Answer 7

Phonological storage depends on posterior parietal corticies
Rehearsal partially depends on Brocas area

Question 8

Areas involved in visuospatial working memory

Answer 8

representation in the parietal, inferior temporal and extrastriate occipital cortices
These representations are modulated by the frontal and premotor cortices

Question 9

Processing episodic memory

Answer 9

Encoding, storage, consolidation, retrieval

Retrieved memories become active again which means old memories can be encoded again

Question 10

Experiment on retrieval

Answer 10

Partially vs fully cut corpus callosum for top down retrieval (stimulus shown on different sides) shows that the prefrontal cortex contributes to recall of associated knowledge

Question 11

Experiment on consolidation

Answer 11

Shows that during sleep or after active behaviour there will be replay of sequences that occurred during the active behaviour.
Studied using place cells in the hippocampus of rats

Question 12

Experiment on habituation

Answer 12

Performed on aplysia studying gill withdrawal reflex
Habituation occurred by depression of synaptic potentials between sensory & motor neurons (sensory still reacts but motor doesnt)

Reflex came back after a while (not forgotten just repressed)

Question 13

Neural pathway of learned fear

Answer 13

Can go direct from thalamus or indirect via cortex (eg auditory). Goes to lateral nucleus of amygdala, then central nucleus

Question 14

Wernickes aphasia

Answer 14

Sensory or receptive aphasia
Fluent speech, little repetition
Adequate syntax and grammar
Contrived/inappropriate works
No comprehension

Therefore: wernickes = comprehension of language (perceive and analyse language)

Question 15

Brocas aphasia

Answer 15

Motor/expressive/production aphasia
Halting speech
Tendency for repetition
Disordered syntax & grammar
Comprehension intact

Therefore: brocas area = how to produce words

Question 16

Right vs left hemisphere functions for language

Answer 16

Left (slightly thicker temporal lobe):
Lexical and syntactic language
Writing & speech
->this is where brocas and wernickes areas are

Right:
Emotional colouring of language (inflection and emphasis)
Rudimentary speech
-> right does spatial tasks

Question 17

What is alexia & lesion that causes it

Answer 17

word blindness: ability to write but not read it back

Can recognise individual letters but not associate them as sounds

Lesion causing it destroys left visual cortex and interrupts fibers from right visual cortex to on their way to left hemisphere language centers

Question 18

gene thought to be involved in language

Answer 18

FOXP2

Question 19

Schaffer collateral synapses

Answer 19

Use NMDA receptors for LTP of synapse

Question 20

where & what are place cells

Answer 20

in the hippocampus, activity correlates with specific places in the environment
Are active when youre in a certain place AND if something happens in that place (association)

NOT topographically mapped (place identities are incredibly labile - adjust to every different environment we can be in)

Question 21

where & what are grid cells

Answer 21

in the medial entorhinal cortex, fire at discrete intervals (mapping different points in our environment)